A man with a fetish for cow manure has been jailed for five years for threatening to kill a family who lived on a farm he targeted.

David Truscott, 43, repeatedly rolled around naked in liquid manure, called 'slurry', at a farm he had developed an obsession with in Redruth, Cornwall.

Exeter Crown Court heard that Truscott, formerly of Camborne, Cornwall, targeted the property over an eight-year period to satisfy in his bizarre craving, and was jailed several times as a result.

He initially removed cow pats from Woodbury House Farm but his behaviour escalated so that Truscott regularly entered the farm in search of slurry.

When the farm's occupants Clive and Jackie Roth erected bollards and removed slurry in a bid to deter him, Truscott decided to exact revenge.

He repeatedly set fire to the Roths' shed, tractor, enclosures and hay - killing a calf in one blaze.

Last year, he admitted making threats to kill the Roth family and damaging their property.

On Friday, he was handed an extended sentence of 10 years following psychiatric reports.

Judge Philip Wassall told Truscott: "When the family took steps to clear up the slurry ... to prevent you from wallowing in it and took other measures to stop you getting on to their land, you began these offences.

"During a prison visit in August 2012, you made a reference to Raoul Moat and said you wouldn't mind going to prison knowing that your revenge would have been received.

Exeter Crown Court, where the case was heard

"The impact on this unfortunate family, who you chanced upon and whose lives you have blighted for years, has been substantial.

"They live in fear of seeing you again."

Prosecuting, Eleanor Purkis revealed that he had previously received a 16-week sentence for stripping naked in the cattle pen, releasing the cattle and climbing into the slurry spreader.

On his release, Truscott returned to the farm and sat naked in cow muck. He was jailed for a further 20 weeks.

He was jailed again, for two years, in September 2011 after police caught him naked in a field harassing the Roth family.

His latest offending was in June last year, when Truscott told support workers he wanted to "get revenge" on Mrs Roth and her 17-year-old son.

"He said 'I will buy a car with the £2,500 I have in my wardrobe and I will drive to Cornwall. I will kidnap them and I will burn them," Ms Purkis said.

Judge Wassall said Truscott, who has autism spectrum disorder, would spend the first five years of his prison sentence receiving hospital treatment.

He will serve an extended licence period of five years on release from prison.

The judge also imposed an extended restraining order to keep him from the farm.